Various polymer stabilizers are used, for improving the processing stability of a polymer (for example, non-patent document 1).
(non-patent document 1)
Seiichi Homma, 1. Kiso Sogo Kaisetsuhen, Genba de Yakudatsu Seikei Kako Gijutsu-Zairyo to Seikei Gijutsu, PLASTIC, 2002 April edition, additional volume p. 4, published by Kogyo Chosakai Publishing, Inc.